Braking system for automotive vehicles



'Nov. 10, 1942.- M. LEUPOLD. 2,301,218

BRAKING SYSTEM FOR AUTOMOTIVE VEHICLES Filed March 7, 1941 3 Sheets-Sheet l IN'VENTOR:

Mal/ads Lew/d BY ATTORN NOV. 10, M,

BRAKING SYSTEM FOR AUT OMO' IIVE VEHICLES Filed'March 7. 1941 s Sheets-Sheet. 2

Nov. 10, 1942. LEUPOLD 2,301,218 Q BRAKING SYSTEM FOR AUTOMOTIVE VEHICLES Filed March '1, 1941 s Shuts-Sheet 3 72 zgjfi INVENTOR:

fla'fkz'as 1.6140010 ATTORNE Patented Nov. 10, 1942 UNiTED STATES BRAKING SYSTEM FOR vEH cLEs AUTOMOTIVE Mathias Leupold, Jamaica, N. Y.

Application March 7,

g 7 Claims.

This invention is a new and useful improvement in braking systems for automotive vehicles.

One object of this invention is a new and use- :ful improvement in braking control for automotive vehicles by using the customary accelerator or accelerator treadle to also control the brakes of the vehicle so as to enable the driver to safely and quickly control the movement of his vehicle by one foot movement-downward for accelerating and upward for stoppingresulting in safer, faster and quicker control of the vehicle.

Another object of this invention is to provide auxiliary means to effect the upward or decelerating movement of the operating treadle with the same relative intensity as the power medium in the power cylinder that actuates the brake pedal or (where no brake pedal is used) brake applying mechanism.

Another object of this invention is the construction of this auxiliary treadle actuating means in such shape that no pressure and very little friction is left therein which would impede the easy and normal operation of the treadlein its accelerating range.

The invention will be fully understood from the following description read in conjunction with the drawings, in which Fig. 1 is a longitudinal vertical section through one embodiment of my invention; A i

Fig. 2 is a longitudinal vertical section through an alternative embodiment oi my invention;

Fig. 3 is a top view of part of the construction shown in Fig. 1;

Figs. 4, 5 and 6 are central vertical sections through a part of the construction shown in: Fig. 3 showing the moving parts in different operative positions;

Fig. '7 is an end view of the construction shown in Figs. 4-6 inc;

Fig. 8 is a View of part of the construction shown in Fig. 7 on the plane indicated by 88;

Fig. 9 is a central horizontalsection through the construction shown in Figs. 4-6 1110.;

Fig. 10 is a central vertical section through an alternative embodiment of one element of my invention; Fig. 11 is an end View of the construction shown in Fig. 10;

Fig. 12 is a front view of the construction shown in Figs. 10 and 11; I

Fig. 13 is a rear View of the construction shown in Figs. 10-12;

Fig. 14 is a central vertical section through a further alternative embodiment of one element of my invention; I I

1941, Serial No. 382,122 o1. 192 3 Fig. 15 is an end I r 7 view of the construction shown in Fig. 14;

Fig. 16 is a front view of the construction shown in Figs. 14 and 15; and

Fig. 17 is a rear view of the construction shown in Figs. 14-16 inc.

Referring to Fig. 1, I designates an automotive vehicle of the type driven by internal combustion engine 2 equipped with intakemanifold 3 communicating through duct 4 with carburetor 5. Insofar as my specific invention is'conc'erned, the intake manifold is a convenient source of vacuum and any other means of producing vacuum, such as avacuum pump, may be equiva- 1" lently employed. Flow of mixture from the carburetor through the duct is controlled by the usual butterfly valve operated by arm 61'- "Ifhe arm 6 is controlled through intermediate connections (not shown) by the push 'rod 1 which 8. In its movement downwardly'from the position shown in solid outlinein Fig. 1, this treadle operates as an accelerator to determine the amount of combustible mixture fed to the engine l from the carburetor. Itis, however adaptedfor movement upwardly beyond the position shown in solid outline in'Fig. 1 to theposition shown in dotted outline in Fig. 1 and Within this range operates through the mechanism hereinafter more fully described to controllably apply the 1 this problem by so constructing the accelerator pedal and ancillary equipment that the brake is automatically applied by the further upward movement of the accelerator pedal. Suchsystems, however, present the difficulty that there Y-is no precise control over the extent of the braking action or at most a relatively inexact control. In theapparatus which I have invented and which is hereinafter described, however, the desired advantages are retained while the specific 535) disadvantages are eliminated and the extent of the braking action issubject to the precise and exact control of the operator by the extent to which he permits the accelerator pedal'tov rise. Moreover, in one embodiment of my invention the operator can feel the'exactextent to which bears against and is actuated by the foot treadle' the braking system is applied since the force urging the treadle upwardly is, within the braking range, exactly proportional to the degree of braking action.

Within the range of acceleration and up into the braking range the treadle 8 may be urged upwardly by any suitable spring not shown. This may also, if desired, be used to urge the treadle upwardly within the braking range.

The automobile I is equipped with a suitable braking system which in the specific embodiment illustrated is of the hydraulic type, and for this purpose the automobile is provided with the foot pedal ll] connected to lever pivotally carried by the stud l2 which is in turn carried by the depending bracket 3. The lever arms [8 and I5 are integral with the lever II. The arm I5 is pivotally connected to the push rod l6 which operates the master cylinder ll of the hydraulic braking system. The arm i8 is pivotally connected to piston rod I9 of power cylinder 29. Power cylinder 2!] is pivotally connected by stud 2| to the chassis of the car. The power cylinder shown in Fig. l is of the single line type in which the piston rod is normally extended and the piston is normally in the end 22 of the power cylinder, but is retracted back into the cylinder to operate the braking system by the application of vacuum to the end 23 of the power cylinder. This kind of power cylinder is alternatively referred to in the trade as an air suspended power cylinder. For this purpose the end 23 of the power cylinder is connected through duct 25 to three-way valve 26 which in turn is connected to duct 24 leading to the intake manifold. Fig. 3 is a top view of the valve 26 from which it appears that the tube 24 from the intake manifold is connected to neck 21 at the forward end of the valve. The treadle 8 is pivotally connected to the right-hand side of the valve while neck 23 is open to the atmosphere. By reference to Fig. 9 it will be seen that the ring 29 constituting the lower end of the treadle 8 is secured by set screw 30 to a sleeve 3| carried by the ends 32 and 33 of the valve which are bored to form bearings or journals within which the sleeve may turn. Journaled within the sleeve itself is a channeled plug 34, one end 35 of which projects beyond the left-hand side of the valve. The projecting end 35 is slotted to receive the'lever arm 33 secured in position by set screw 3'1. The arm 36 (Fig. 1) is pivotally connected to the push rod 31, pivotally connected to the lever l5.

It is evident from the foregoing that the sleeve 3| is connected to and turned by the treadle 8, whereas the plug 34 journaled within the sleeve 3| is connected to and turned by the braking system. The housing 3i! of the valve defines ports while the sleeve 3| defines longitudinal slots and the plug 34 defines longitudinal channels, the function of which will be apparent from Figs. 4-9. Referring to Fig. 7, the ports are three in number and are indicated by the dotted outlines 40, 4| and 42. As is evident from Fig. 9, these ports extend the full width of the valve up to the journals 32 and 33. In the center sections of the valve shown in Figs, 4-6 inc., these ports converge into the ducts 43, 44 and 45 defined by the threaded necks 45, 4'! and 48. The sleeve 3| defines slots 53, 5| and 52 which slots extend the full length of the said ports leaving the sleeve unslotted within the areas covered by the journals 32 and 33. The plug 34 defines channels 53 and 54. These channels extend the full length of the slots 50, 5| and 52, while the ends of the plug 75' within the area overlain by journals 32 and 33 are not channelled.

In the set-up shown in Fig. l, the tube 24 leading from the intake manifold is connected to the threaded neck 46, neck 48 is open to the air, while threaded neck t! is connected to tube 25 communicating with end 23 of power cylinder 20.

In Fig. 4 the sleeve and plug are shown in the relative positions they occupy when the brake is unapplied and the treadle is in the accelerating zone, i. e., when it is depressed below the position shown in solid outline in Fig. 1. In this position it will be seen that there is free communication between neck 48 and l! through duct 45,

port 40, slot 50, channel 53, slot 5!, port 4|, and

duct 44. This communication is maintained throughout the entire range of acceleration, since the ports 40 and 4| are wide enough to overlie the slots 5| and 5?) in any part of this range.

In Fig. 5 the sleeve 3| and plug 34 are shown in the neutral position, i. e., with the brake unapplied and with the accelerator in neutral position shown by solid outline in Fig. 1. In this position it will be noted that there is no communication through the valve 26. When, however, the accelerator pedal moves upwardly into the braking region, the sleeve 3| moves in the direction shown by arrow 5! (Fig. 6). In this position the vacuum of the intake manifold from tube 24 is thrown into communication with tube 25 leading to the power cylinder through neck 46, duct 43, port 42, slot 52, channel 54, slot 5|, port 4| and duct 44. In this way vacuum is applied to end 23 of power cylinder 2!! with the consequent retraction of piston rod l9 and the application of the brakes. As the braking system moves, however, rod 31 and lever 36 (Fig. 1) rotates plug 34 in the direction shown by arrow 51 (Fig. 6), whereupon that portion of plug 34 between the channels 53 and 5G overlies slot 5| and interrupts communication, and insures that the application of the braking system will be arrested at any point determined by holding the treadle stationary. For maximum precision the width of the raised portion of plug 34 should be exactly equal to the width of slot 5|. Sleeve 3| carries a stop 50 which by contacting with lever 36 limits the motion of the. sleeve and treadle with respect to the braking system (Figs. '7 and 8) so that the treadle will maintain a position slightly in advance of the braking action.

In Fig. 2 I have illustrated an alternative type of power cylinder of the dual line type. In this case ends BI and 62 of power cylinder 63 are normally both subjected to vacuum. The end 62 is continuously subjected to vacuum through tube 64 communicating with intake manifold 3. The end BI is usually subjected to vacuum and the power cylinder is operated by admitting air into the end 6| which sets up a pressure differential retracting piston rod Is. This kind of power cylinder is alternatively referred to in the trade as a vacuum suspended power cylinder. The same valve structure is employed connected to .the treadle and the braking system in the same way and neck 41 of the valve is connected through tube 65 (Fig. 2) with end 6! of the power cylinder. Tube 66 communicating with the intake manifold is, however, carried to the neck 48, while neck 46 of the valve is open to the air. As aforesaid, with the brake in neutral or unapplied position, and the treadle in the accelerating range, there is free communication between necks 48 and 41, with the resultant fullapplication of vacuum to the end 6| of theypower cylinder. When, however, the treadle moves in the braking range, this communicationis. interruptedand air from the neck 46 (Fig, 6) isadmitted-into end 6| of the power cylinder, setting upapressure differential, thereby applying the brakes, and whenever the braking system has advancedto a point determined bythe position of the treadle, the introductionof air is arrested,;

and the brakes are held at the point so determined. .It is evident that any downward movement of the treadle withinzthe braking range .reverses the port connection and operates conversely to release the brake until a release position is arrived at deter-mined by the position of the treadle.

In Figs. 10-13 inc., I have shown an alternative form of three-way control valve. This specific form is adapted for use in the-systemshown in Fig. 1 in which the power cylinder issingle line. This valve I includes the housing 'II- defining longitudinal ports 1 2, I3 and I4, communicating respectively, with the threaded necks I5, Hand 11. Neck I5 is connected to tube 24 running from the intake manifold; neck I6 is connected to tube 25 running to end 23 of the power cylinder, While neck I1 is open tothe air. Sleeve 80 is connected to the treadle in the manner hereinbefore described while plug BI isconnected to the braking system. The sleeve 80 is carried in the journaled ends 82 and 83 of the housing II (Fig. 13). The ports I2, 'I3and I4 extend up to the journals and the slots 84, 85 and 86 similarly extend the full width of the ports,-i. e., up to but not intothe area overlainsby the journals 82 and 83. 81 and 88, which extend up to but not into the area overlain by journals 82 and 83. Thedistinguishing feature of this construction is that the longitudinal ports I3. and I4 define -,a-segmentor section 90 (Fig. 10) which is of arcuate cross-section concentric with axis of rotation 0|, while the sleeve 80 carries a projecting ,fiap

or vane piston 92, that fits snugly into this ar-.

cuate section forming therewith a substantially gas-tight seal and extendingup to the ends of the arcuate section to which it snugly conforms. Within the section 90', however, the vane piston has clearance radially and at the ends aswell the housing being cut back to allow end clearance and eliminate any friction between housing and vane piston within the accelerating range. When the treadle isin neutral sition, this flap or piston depends vertically into the position shown in dotted outline in Fig. 10; slot 84 is out of the range of port I2 andair moves freely from neck.- 11 to neck I6 around the vane piston, as well as through slot 86, channel 88 and slot 85, and thence to tube to end 23 of powerwcylinder 20. When, however, the treadle is permitted to move up into the braking range, this communication is broken while neck I5 connected to tube 24 is placed into communication with neck I6 communicating with tube 25 through port I2, slot 84, channel 81, slot 85 and port I3. Within this range it will benoted thatport I3 is,under vacuum, there is, therefore, a difierentialpressure urging the vane piston -92 in the direction indicated by arrow 93 (Fig. 10). This insures that there will be an upward pressure on the treadle functionally dependent on the exact extent to which the braking system has been applied.

The form of valve shown in Figs. 1417 inc., is similar in principle but specifically adapted The plug 8I also defines channels for'use in the system shown in 2 in which the-power'cylinder is dual control. In this case the valve I00 includes housing IOI defining 1ongitudinal ports I02, I03 and I04 communicating respectively with threaded necks I05, I06 and [01,- These ports extend the width of the housing;up to the journaled bearings I05 and I06. Thez'neck I 01. is connected to tube 66 leading fromthe intake manifold, while the neck I06 is connected to-tube 65 leading to end 6| of the power cylinder and neck I05 is open to the air. The port I04 defines an arcuate section concentric with the axis of rotation I08 of sleeve I09. Sleeve I09 defines the slots H0, III and H2 and carries the flap or vane piston II3 adapted to move in the arcuate section I04 of the port I04, making a-snug and substantially gas-tight contact therewith both radially and at the ends of the vane piston. Within the section I04", however, the vane piston has clearance both radially and at the ends the housing being cut back to allow clearance and eliminate any friction between housing and vane piston within the accelerating range. The slots H0, III and H2 extend the full width of the sleeve up to but not into the area overlain by the journals or bearings I05 and I06. The plug H5 defines a single longitudinal channel IIB extending up to but not into the area overlain by. journals 105 and I06. The valve is shown in Fig. 14 with the ports in neutral position and with. the vane piston II3 projecting vertically downward. In this position neck I01 is in free communication with neck I06 through port I04, slot II2, channel II6, slot III and'port I03. There is no differential pressure on piston H3. When, however, the treadle moves up into the braking range, slot H2 is overlain by plug H5, thereby breaking communication between necks I01 and I06. Simultaneously, slot IIO moves down into registry with port I02, thereby setting neck I05 in communication with neck I06through port I02, slot H0, channel H6, slot I I I and port. I03. Inasmuch as the side of piston II3 exposed to port I04 is continuously subject to vacuum, there is a differential pressure urging the treadle upwardly and providing the operator with. an upward pressure functionally proportional to the extent to which the brakes have been applied.

In both the systems shown inF'igs. 10-l3, and. 14-17, the spring which urges the treadle upwardly must move itslightly beyond the neutral position and into-the commencement of the braking range, where the pressure differential takes hold. With the valve shown in Figs. 11-15, inc., a stop 69 is provided (Fig. 11) projecting from the sleeve which has the same function as stop 60 previously described. With the valve illustrated in Figs. 15-17 stop I08 (Fig. 15) is similarly provided carried by sleeve I09 and which similarly functions by contact with lever 36.

The. effect in either case is to insure that the treadle in the braking range will move upwardly only insofar as the braking system is applied, thereby insuring a gradual and accurately controllable braking eflect.

While I usethe word treadle in the specificatien and claims, it will be understood that I mean to include the foot pedal and similar means that operate by movement in-a vertical plane to control the acceleration, of the vehicle.

It will be understood that the foregoing description is for purposes of illustration and not of limitation, and it is'therefore my intention that the invention be limited only by the following claims or their equivalents wherein I have endeavored to claim broadly all inherent novelty.

I claim: 1. In an automotive vehicle including means for producing vacuum, and including a braking system and a dual line power cylinder operatively connected to said braking system and having a first end connected to said means for producing vacuum, a treadle controlling the acceleration of said vehicle in its downward movement from idling position and adapted for movement upwardly from idling position, a three-way valve adapted to alternatively place the other end of said power cylinder in communication with said means for producing vacuum and with atmospheric pressure, said three-way valve being A operatively connected to said treadle and adapted to open to place the other end of said power cylinder in communication with atmospheric pressure in response to the movement of said treadle upwardly from said point, a cut-off following the movement of said valve operatively connected to said braking system, blocking said last mentioned opening when the braking system reaches a point of application determined by the extent of upward movement of said treadle.

2. In an automotive vehicle including means for producing vacuum, and including a braking system and a power cylinder operatively connected to said braking system, a treadle controlling the acceleration of said vehicle in its movement downwardly from idling position and adapted for movement upwardly from said idling position, a three-way valve adapted to alternatively place said power cylinder in communica tion with said means for producing vacuum, and with atmospheric pressure, said three-way valve comprising a tubular sleeve defining slots journaled for rotational movement and operatively connected to said treadle, a housing surrounding said sleeve defining ports, means connecting said ports respectively with said means for producing vacuum with said power cylinder and with atmospheric pressure, said valve being adapted to open to operate said power cylinder in response to the movement of said treadle upwardly from idling position, a channeled plug journaled in said sleeve, said plug being operatively connected to said braking system and adapted to overtake said sleeve and block said last mentioned opening when the braking system reaches a point of application determined by the extent of upward movement of said treadle.

3. Apparatus according to claim 2 in which said tubular sleeve carries a vane piston and said housing defines a chamber of arcuate section within which said vane piston moves when said treadle is upwardly with respect to idling position and the said ports are so arranged that when said vane piston is in said arcuate section, the vane piston is subject to a pressure difierential urging said treadle upwardly with respect to idling position.

4. In an automotive vehicle including means for producing vacuum, and including a braking system and an air suspended power cylinder operatively connected to said braking system, a treadle controlling the acceleration of said vehicle in its movement downwardly from idling position and adapted for movement upwardly from said idling position, a three-way valve adapted to alternatively place said power cylinder in communication with said means for producing vacuum, and with atmospheric pressure, said three-way valve comprising a tubular sleeve defining slots journaled for rotational movement and operatively connected to said treadle, a

housing surrounding said sleeve defining ports, means connecting said ports respectively with said manifold with said power cylinder and with atmospheric pressure, said valve being adapted to open to place said power cylinder in communication with said means for producing vacuum in response to the upward movement of said treadle from idling position, a channeled plug journaled in said tubular sleeve, operatively connected to said braking system, said plug being adapted to overtake and block said last mentioned opening when the braking system reaches a point of application determined by the extent of upward movement of said treadle.

5. Apparatus according to claim 4 in which said tubular sleeve carries a projecting vane piston and said housing defines a chamber of arcuate section within which said vane piston moves when said treadle is upwardly with respect to idling position and the said ports are so arranged that when said vane piston is in said arcuate section, the vane piston is subject to a pressure differential urging said treadle upwardly with respect to said point.

6. In an automotive vehicle including means for producing vacuum, and including a braking system and a dual line power cylinder operatively connected to said braking system and having a first end connected to said means for producing vacuum, a treadle controlling the acceleration of said vehicle in its movement downwardly from idling position and adapted for movement upwardly from idling position, a three-way valve adapted to alternatively place the other end of said power cylinder in communication with said manifold, or with atmospheric pressure, said three-way valve comprising a tubular sleeve defining slots journaled for rotational movement and operatively connected to said treadle, a housing surrounding said sleeve defining ports, means connecting said ports respectively with said manifold with said power cylinder and with atmospheric pressure, said valve being adapted to open to place the other end of said power cylinder in communication with atmospheric pressure in response to the movement of said treadle upwardly from idling position and a channeled plug journaled in said tubular sleeve operatively connected to said braking system and adapted to overtake and block said last mentioned opening when the braking system reaches a point of application determined by the extent of upward movement of said treadle.

7. Apparatus according to claim 6 in which said tubular sleeve carries a projecting vane piston and said housing defines a chamber of arcuate section within which said vane piston moves when said foot pedal is upwardly with respect to idling position and the said ports are so arranged that when said vane piston is in said arcuate section, the vane piston is subject to a pressure diiferential urging said treadle upwardly with respect to idling position.

MATHIAS LEUPOLD. 

